アンケート調査に基づく建物内の振動に対する心理的反応の評定尺度構成

 In the psychological measurements of subjective responses to vibration, the category rating scale method has been adopted in previous studies. Since the rating scale methods ask judgment with adverbial expressions used in daily life, it is generally said that respondents could make judgement relatively easily. On the other hand, since the degree of sensation represented by semantic labels used for each category in the scale is often not clear and vary between individuals, a selection of semantic labels for categories in the scale can result in unclear boundaries between categories and unequal intervals between categories on sensory scale.<br> This study conducted a questionnaire survey on 23 kinds of adverbial expressions that could represent subjective responses to vibrations. Those expressions were selected with reference to previous studies on noise. From the results of questionnaire survey, appropriate adverbial expressions were then selected for each category in 5- and 7-step rating scales. In addition, an experiment involving human subjects was carried out using an electrodynamic shaker in a laboratory to investigate relationship between vibration intensities and ratings measured with the scale developed from the conceptual questionnaire.<br> The questionnaire survey investigated adverbial expressions representing the degrees of three kinds of subjective response to vibration, i.e., "Magnitude", "Concern", and "Discomfort". The number of categories in the scale was set to 5 and 7 steps. An internet survey was conducted all over Japan regardless of gender, age, etc. The number of respondents in this survey was 1,700 for 5- and 7-step scales in total, of which the number of effective respondents was 851 for 5-step and 857 for 7-step. In accordance with the criteria for the selection of expressions suggested by ICBEN (International Commission on Biological Effects of Noise) Team 6, the adverbial expressions for 5 and 7-step were selected. The effects of age, gender, area of residence, and experiences of building vibration exposure on the rating scale were investigated statistically. It was found that, although there were statistically significant differences in the interpretation of some adverbial expressions between different groups of respondents, those differences were not sufficient to give any effects on the orders and intervals in the scale developed.<br> In the complemental experiment, the method of adjustment was adopted to measure the subjective intensity produced by vibration corresponding to adverbial expressions of 23 kinds directly. In the experiment, "Magnitude" and "Concern" only were investigated. The amplitude of sinusoidal vibration at a frequency of 4 Hz was determined for each of the 23 adverbial expressions by adjustment method. The frequency was set to 4 Hz which is often found in the horizontal first order natural frequency of a steel-framed residential building to represent a horizontal vibration inside building. The experimental results showed a reasonable relationship between vibration intensities and the degrees of sensation determined by adverbial expressions in the questionnaire conceptually. The regression line between conceptual strength of vibration sensation and physical quantity of vibration indicated a logarithmic law.